Web tensioning means



May 5, 1953 K. G.- LAYcocK WEB TENsIoNING MEANS 2 SHEETS-SHEET l FiledJan. 28, 1950 7D PRESS INVENTOR. f/v/VETH 6. LAYCOCK ATTORNEYS.

May 5, 1953 K. G. LAYcocK WEB TENsIoNING MEANS 2 SHEETS-SHEET 2 FiledJan. 28, 1950 7'0 PRESS` [fill/i114 INVENTOR. /fE/v/vT/f 6. fn/cach BYATTURNL'YS.

Patented May 5, 1953 UNITED STATES PATENT OFFICE 2,637,505 WEBTENsIoNING MEANS Kenneth G. Laycock, Shavertown, Pa. Application January28, 1950, serial No. 141,127

The present invention relats to new and useful improvements in webtensioning devices for automatically controlling the tension of a paperweb as it is fed from a web roll to a rotary printing press.

Objects and advantages of the invention will be set forth in parthereinafter and in part will be obvious herefrom, or may be learned bypractice with the invention, the same being realized and attained bymeans of the instrumentalities and combinations pointed out in theappended claims.

The invention consists in the novel parts, constructions, arrangements,combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a parthereof, illustrate one embodiment of the invention, and together withthe description, serve to explain the principles of the invention.

Of the drawings:

Figure 1 is a side elevation with certain parts broken away showing atypical and preferred embodiment of the present invention;

Figure 2 is a detailed sectional view taken o the line 2 2 of Figure 1;

Figure 3 is a transfer sectional view taken on the line 3--3 of Figure1;

Figure 4 is a fragmentary side elevation of the embodiment shown inFigure 1 but looking from the other side thereof; and

Figure 5 is a detailed side elevation of a modication of certain parts.

The present invention has for its object the provision of a novel andimproved web roll tensioning device adapted to maintain a uniformtension on the web of paper as it is drawn from the web roll by therotary printing press to which it is being fed. A further object of theinvention is the provision of an improved web tensioning device whichmaintains the tension substantially constant regardless of the diameterof the web roll and the speed at which the web is drawn from .sults fromits use and the better understanding of the functions of web tensioningin general that it teaches through its simple, easily understoodadjustments and its'very efficient action. 1 vIn accordance 4with thepresent-- invention,

16l claims. (o1. 242-75) ymass and the pilot roller is illustrativelyprovided 'meansare provided for applying friction to a web rollsupported for rotation, and these tensioning means are controlled Aby apilot roller which is moved in accordance with changes in the webtension and is so connected as to increase or decreasethe frictionapplied to the web roll. The pilot roller is supported in pivotallymoveable arms, and when moved by an increase in the web tension causes adecrease in the friction applied to the web roll. The movement of thepilot roller, and the transmission of this movement to the brake orother means for applying friction to the web roll is also controlled bya relatively heavy mass which is resiliently connected to the pilotroller through spring linkage having variable resiliency so that thestrength of the spring can be varied and maintained at the desired valuethereby regulating the effect of the mass on the pilot roller. Means arealso provided for restraining the free movement of the suspended massand for this purpose friction braking or snubbing means are providedwhich exert more restrainton the mass in one direction of movement thanin the other.

The connection between the spring supported by an arcuate saddle xed tothe pilot roller supporting arms and coaxial with the Divot for the armsbut also moveable radially with respect to the pivot so that the leverarm ratio betweenthe supporting arms and the surface of the arcuatesaddle may be varied as desired.

It will be understood that the foregoing general description and thefollowing detailed description as well are exemplary and explanatory ofthe invention but are not restrictive thereof.

Referring now in detail to the illustrative embodiment of the invention,the web roll I0 is supported by means of its shaft Il and journals l2formed in brackets I3 which extend laterally from the upright framemembers I4, similar supports being provided at either end of the webroll I0. Tension is created in the web I6 drawn from the web roll lil bymeans of a brake which comprises brake drum I8 and brake shoes I9, thebrake shoes being pressed toward each other and into contact with thedrum i8 by means of the lever arms 20 which are pivotally supported by alink 22 mounted on the frame member I4 by means of the side vlayadjusting wheel 24. The other ends of the brake levers 20 areinterconnected by means of upper end of the link 25 with the adjacentend of the upper brake lever arm 2B. The length of the link 26 may bevaried to compensate for wear of the brake shoes I9 by turning the screwthreaded member 3|.

As the web is drawn from the web roll I to the printing press it passesover guide rollers 34 and 35, and between them is looped over pilotroller 31 which is freely rotatable in supporting arms 38 which arepivoted in the upright frames I4 by means of shaft 33, and arepreferably counterbalanced by means of the variably positioned weight40. Also mounted on shaft 39 in fixed angular relation to the arms 38 isa depending arm 4| (see Fig. 3) which is operatively connected to thebrake operating arm 29 by means of link 43. An increase in the tensionof the web fed to the press causes the pilot roller 31 to movedownwardly thereby moving bell crank 28 in a counterclockwise directionto relieve the pressure on the -brake shoes I9 so as to permit web rollID to rotate more'freely and therebv effect a reduction in the tensionof the web. Simultaneously a decrease in the tension of the web causes areverse movement of these parts so that the brake pressure exerted byshoes i9 is increased to increase the web tension.

The tension of the web I5 also tends to move the pilot roller againstthe force exerted by a relatively heavy mass 5@ which is connected withthe pilot roller bv means of rod 52, spring linkage 54, rod 5G, exiblecable 58 and an arcuate saddle 6U-coaxial with and xed to shaft 39 onwhich the pilot roller supporting arms 38 are mounted. By these meansmass 50 rnoves up and down in accordance with movements of the pilotroller 31, and in the same wav controls the position of the pilot roller31 and the force applied by the braking shoes I9.

Mass 5I] comprises a cylinder of heavy metal supported on a collar 62 atthe lower end of rod .52, and the value of this mass may be varied byadding or removing the supplementary slotted members 50a.

The spring linkage of variable resiliency forms an intermediateconnection between the rods 52 and 55, and the weight of the entire mass5B is supported by this spring linkage and the connection between themass 5|) and the pilot roller 31 is through this spring linkage. Thespring linkage 54 comprises a pair of lever arms interconnected by ashiftable pivot at one end and by a spring at the other end, one of thelever arms being connected at an intermediate point to the rod 52 whilethe other lever arm is connected at an intermediate point to the rod5K5. As embodied this linkage comprises a bottom pair of short straps 64forming a lever and an upper pair of short straps 58 forming anotherlever, which levers are normally substantially parallel to each other.At one end the straps E4 and 66 are interconnected by means of a linkwhich comprises rod 68 fastened to a pivot block I pivoted between thestraps 64 and extending upwardly and slidably through a pivot block 12pivoted between the ends of straps 65. A compression spring 14 ismounted on the rod 63 and is compressed between the slidable pivot block12 and. the iam nuts 15.

At the other end the lever arms 64 and 63 are interconnected by means ofa horizontally slidable link 18, having upper and lower pins 19 whichcooperate with the slots 3S to provide the variably positionable pivotalconnection between the lever arms'. For positively moving the link 18and holding it in the desired position, a bracket 82 is fixed to andextends upwardly from the lever arm 64 and carries hand wheel 84 havinga threaded portion which extends through a threaded aperture in the link18. Rotation of the hand wheel 84 moves the link 18 toward and from rodE8 serving as the link at the other end of the lever arms. Between thelinksl 58 and 18, the lever arm is pivotally connected to the rod 56 andshifting of the link 'I8 varies the effective resiliency of thecompression spring 14. Lever arm @t is preferably rigidly connected torod 52.

The arcuate saddle 69 provides a variable ratio between the movement ofthe pilot roller 31 and the movement of the mass 59 and is useful inadjusting the web tensioning mechanism for different widths of web aswell as for any other rcason. As embodied the arcuate saddle structurecomprises an arcuate surface 99 to the lower end vof which is fixed theend of flexible cable 5|), the cable extending upwardly from the surface92 so that it is substantially tangential to the surface. Surface iscarried by slide block 92 which is slidably mounted in guides 94 of thebox frame 95 which is fixed on the pilot roller supporting arm pivotshaft 39 so as to have a fixed angular relation to the arms 38. A crank91 connected to screw 98 cooperates with the slide block so that thearcuate surface 90, which is normally co,- axial with shaft 33, may bemoved radially with respect to the shaft 39 thereby changing the loverarm ratio between the pilot roller 31 and the arcuate surface 90.

Flexible cable 58 passes over an idler pulley I lill and is connected tothe upper end of mass supporting rod 58. Rod 55 is slidably guided bymeans of a bracket |02 extending from side frame I4 and which alsoserves as the abutment ier compression springs |94 and |05 wound on rod5S. Collars |68 l-lxed on the rod 56 serve to limit free movement of therod 55, and cooperate with springs |84 and |06 to prevent andresiliently check excessive movement of the rod 55 and the supportedmass 5U.

Means are also provided for frictionally restraining free movement ofthe mass 50 so as to avoid any tendency of the mass to vibrate, andpreventing bouncing by the mass 59 such as might otherwise occur when aweb roll is being run which has a flap, is eccentric, or otherwisedeformed. For this purpose rod 52 is provided with an upwardly taperingwedge member I I0 xed thereto, the converging faces of the wedge beingfrictionally engaged by friction shoes |2. Friction shoes 2 are formedas inner faces mounted on blocks II 4 and each of the blocks I I4 isguided for horizontal movement toward the other in a box IIS dependingfrom bracket IIB mounted on the side frame I4. Blocks H4 and theirfriction faces ||2 are resiliently urged toward each otherby means ofthe levers |20 and compression springs |22 also mounted on the bracket IIt. The force of springs |22 is varied by means'of the screw threadedmember |24 at one end of each lever, the other end of the lever bearingagainst the outer face of the block II4.

In the operation of the preferred embodiment of the invention, a new webroll I0 is mounted on its journals I2 and is threaded over the vguiderolls 34, 35 and the pilot roller 31 and is threaded through the pressfor printing. The brake mechanism is then reassembled and hand wheel 3|is adjusted to bring the brake shoes I9 to their normal position tocompensate for any wear. 'Saddle 9B is then'brought to its propersetting corresponding to the width of the Web-to. .be run and shiftablelink 18 is moved to compensate for any weakening of the spring 14 whichmay have roccurred orto provide a different resiliency in the springlinkage 54. The mechanism is then ready for operation and gradualmovements of the pilot roller 37 in a downward direction causea graduallessening of the friction applied by the brake to the web roll. However,any sudden movement of the pilot roller allows additional web to bepayed out of the loop and while the brake shoes I9 are momentarilyappliedwith decreased force to the web roll, if the movement or thepilot roller 31 is lpurely a momentary movement, it will regain itsnormal position without eiecting any substantial movement of the mass 5Ddue to the resiliency of the spring linkage 54 and the friction means II Il, 'I I2. However, a continued increased in the web tension willcause an upward movement of the mass 5i and a corresponding increase inthe pressure applied to the brake shoes IQ and the tension createdthereby. When the mechanism is at rest, or when the web is running at aconstant and unvarying tension, the weight of the mass 5@ acts upon thepilot roller 3l to maintain the pilot roller at a fixed position as itis balanced against the pull exerted by the web. Any change in webtension causes a slow or rapid movement of the pilot roller 3l which istransmitted to the mass 50, but due to the inertia of the mass 58 rapidmovements of the pilot roller are largely absorbed by the resiliency ofthe spring 'M while the mass 5D remains more or less stationary. Thusthe mass 5t is used not only for its weight but also as an inertiamember.

If it is desired to increase the tension to be normally applied to theweb, the crank 96 may be rotated to move the arcuate surface @il awayfrom its pivotal center .39 thereby lengthening the leverage ratiobetween the pilot roller 51 and the brake connecting linkage as oneentity and the mass .iil and its linkage as another entity therebyincreasing the value of the mass E@ in relation to its applied force.

llhe friction members I ID, I I2 acting to restrain free movement of themass 5), act with greater effect with one direction of movement thanwith the other; a decrease in web tension is corrected more rapidly thanis an increase in web tension. This is not only of importance inproviding for rapid braking of the web roll in case of a web break, butis also of importance in the normal running of the mechanism so as toprevent the web becoming slack at any time in its passage from the rollthrough the press.

Figure 5 illustrates a modified form of spring supported linkageinterconnecting the pilot roller and mass whereby a wider variation ofresiliency is obtainable than with the form shown in Figure l. In Figure5 rod 52 is rigidly and detachably connected to one end of strap 645 bypin A2 and collar Iiiii so that strap t4 is supported by collar IZlagainst pivotal motion relative to the rod 52. Strap 5S is pivotallyconnected by pivot A1 to rod 5t, and the straps 64 and G6 areinterconnected by means of the rod 68, spring lli and pivot blocks 'liland l2 which are pivotally connected by pivot pins B2 and B1 to strapsGil and '55 between their ends. Slidable link 'i8 connected the otherends of straps 5d and SG as in Figure l. In the position shown in Figure5 the spring 'isihas a soft action and it can be given the eiiect or" amuch stiiier spring by connecting the rods 52 and 56 at pivot points B2and Bl and by connecting the pivot blocks 'lli and 'I2 at the pivotpoints A2 and A1.

The present invention in certain respects is an improvement upon the webtensioning apparatus 6 shown and described in my copending applicationSerial No. 8,179 led' February 13, 1948,- butin other respects it is notso limited and is of more general application;

The invention in its broader aspects is not limited to the specificmechanisms shown and described but departures may be made therefromWithin vthe scope of the accompanying claims without departing from theprinciples of the invention and without sacricing its chief advantages.

What is claimed is:

1. In a web tensioning device for controlling the tension of a paper webfed from a web roll to va4 rotary printing press, having a web rollsupport, means for applying friction to the web roll to tension the web,a pilot roller moved by changes in the web tension and connected toincrease or decrease the friction applied to the web roll, an increasein web tension causing a decrease in the friction, the combination of amass, and a linkage having variable lever arm ratio connected betweenthe pilot roller and mass, a spring forming part of the linkage, saidlinkage and spring being connected between said mass and pilot rollerfor supporting said mass with a variable resiliency.

2. A web tension device as claimed in claim 1 in which the pilot rolleris supported in pivotally mounted arms, and an arcuate saddle coaxialwith said arms to which said mass is connected by means of a nexiblemember tangential to the saddle.

3. A web tension device as claimed in claim 2 in which means areprovided for radially moving the arcuate s addle. i

4. A web tension device as claimed in claim- 3 in which friction meansare-provided acting on the mass and principally restraining an upwardmovement of the mass.

5. In a web tensioning device for controlling the tension of a paper webfed from a web roll to a rotary printing press having a web rollsupport, means for applying friction to the web roll to tension the web,and a pilot roller moved by changes in web tension and connected toincrease or decrease the friction applied to the web roll, an increasein web tension causing a decrease in the friction, the combination of amass spring supported linkage of variable resiliency supported by thepilot roller and through which the mass moves and is moved by the pilotroller.

6. A web tension device as claimed in claim 5 in which said springsupported linkage comprises a pair of levers, a spring connected to oneend of each lever, and a shiftable pivot means interconnecting thelevers at their other end.

7. A web tension device as claimed in claim 6 having arms pivotallysupporting the pilot roller, an arcuate saddle xed to and coaxial withsaid arms and a flexible band connected to the mass and tangentiallyconnected to said saddle.

8. A web tension device as claimed in claim 7 in which screw means areprovided for radially moving the arcuate saddle to vary its positionrelative to the pilot roller supporting arms pivot.

9. In a web tensioning device for controlling the tension of a paper webfed from a web roll to a rotary printing press having a web rollsupport, means for applying friction to the web roll to tension the web,a pilot roller moved by change in web tension and connected to increaseor decrease the friction applied to the web roll, an increase in webtension causing a decrease in the friction, the combination of a mass,and spring 7 supported linkage connecting the mass to the pilot rollerto support the pilot roller and to move the pilot roller by the mass,said linkage including variable lever arms for changing the resiliencyof the spring linkage.

10. A web tension device as claimed in claim 9 in which said springsupported linkage comprises a pair of levers, a spring connected to oneend of each lever, and a shiftable pivot means interconnecting thelevers at their other end.

11. A web tension device as claimed in claim 10 having arms pivotallysupporting the pilot roller, and an arcuate saddle nxed to and coaxialwith said arms.

12. In a web tension device for controlling the tension of a paper webfed from a web roll to a rotary printing press, the combination offriction means restraining the rotation of the web roll, a pilot rollermoved by changes in the web tension and connected to increase ordecrease the v friction applied to the web roll, an increase in webtension causing a decrease in the friction, a mass for moving the pilotroller against the pull of the web, a pair of pivotally interconnectedlevers, a member flexibly connecting the pilot 2 roller to one lever,another member interconnecting the mass to the other lever, spring meansinterconnecting the levers and acted on by the weight of the mass as themass tends to move the pilot roller and is supported thereby, and

14. In a web tension device for controlling the tension of a paper webfed from a web roll to a. rotary printing press, the combination offriction means restraining the rotation of the web roll, a pilot rollermoved by changes in the web tension and connected to increase ordecrease the friction applied to the web roll, an increase in webtension causing a decrease in the friction, a mass connected to move thepilot roller against the pull of the web, the connection includinglinkage comprising a pair of levers each having three pivot points,means pivotally interconnecting the levers at one of their pivot points,a spring inter-connecting the levers at another of their pivot points,and the mass and pilot roller being connected to the third pivot pointof the levers whereby the weight of the mass is resiliently supported bythe spring, and means for relatively shifting the several pivot pointsof each lever with respect to each other whereby the effective strengthof the spring may be varied.

15. A web tension device according to claim 14 in which the pivot pointson each of the two levers are similarly spaced, the spring is connectedbetween the central pivot points and the pivotal interconnection betweenthe levers may be shifted towards and from the other pivot points.

16. A web tension device according to claim 15 in which the pilot rolleris connected by linkage to energize the friction means, and the frictionmeans comprises a brake acting on the web roll shaft.

KENNETH G. LAYCOCK.

References Cited in the iile of this patent UNITED STATES PATENTS NumberName Date 1,645,939 Smith Oct. 18, 1927 1,985,292 Horton Dec. 25, 19342,086,068 Cline et al July 6, 1937

